[steve25]

It’s normal for a tall aftermarket duel plane like this which has been cast with more gradual area transitions and bigger radius bends.

In off the shelf form this intake should support 535 to 540 hp, with a 1” or better spacer I would guess that up to 560 hp could be made.

[Steve C.]

Refreshing to see testing done like this, and as eluded to it is a lot of work.
Good job !

As an example briefly take note the amount of work done here in similar testing by Rocky Rotella:

https://www.hotrod.com/how-to/hppp-0...ntake-manifold

Regarding the comment the testing done with no Carb bolted on.

Here is some information that that I brought up in a similar thread that has a tid bit on how the carb might affect results.....

Head flow and the intake manifold are interconnected. The intake effects the total air flow, as does the carb.

Rocky Rotella had some articles published in High Performance Magazine that involves the subject of total air flow thru the intake system. In conjunction with the article he tested the Performer RPM intake as cast on a stock SD-455 cylinder head that flowed an average of 237 cfm at .550" lift. Flow bench tested the RPM intake was just over 92 percent with the SD head. If the percentages stay true as flow goes up, you need head flow in the 260 cfm range to get 240 cfm into the engine. He also tested the flow through carburetors. His Holley HP950 and a Cliff Ruggles modified QJ reduced flow by about another 5 percent. If the QJ is stock, the reduction can be as much as 7 percent depending on the angle of the secondary air valves.

Anyway we can see it can get very involved when you consider the impact of the intake manifold and carb on total airflow.


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